<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			.wrap{
				width: 100px;
				height: 100px;
				background-color: deeppink;
			}
			.test{
				position: absolute;
				/* left top 等的默认值是 auto 并不是 0 */
				/*left: 0px;
				top: 0px;*/
				width: 100px;
				height: 100px;
				background-color: pink;
			}
		</style>
	</head>
	<body>
		<div class="wrap"></div>
		<div class="test">
			
		</div>
	</body>
</html>
